ATHENS (Reuters) - Greece's chief negotiator in aid talks with international creditors, Euclid Tsakalotos, is the government's top candidate to become finance minister following the resignation on Monday of Yanis Varoufakis, a senior government official said. Varoufakis' successor is due to be named after a meeting of political leaders that got under way at 10 a.m. (0700 GMT). (Reporting by Renee Maltezou; Writing by Matt Robinson; Editing by James MacKenzie)